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In Tunisia, the exploitation of the sun and the shores, for nearly 6 decades, has generated a spectacular development of mass seaside hotels. This monoactivity has been responsible for the current tourist crisis with all its dimensions: economic, social and environmental. The political instability, which followed the revolution of 2011, as well as the attacks which hit Tunisia, in 2015, has drastically reduced the number of tourists in the country. These political and security crises were caught up in his convalescence by COVID-19. In reality, the pandemic context would have served as an indicator and an accelerator for the development of "sustainable tourism" instead of mass tourism before COVID. In Tunisia, the exploitation of the sun and the shores, for nearly 6 decades, has generated a spectacular development of the mass seaside hotel industry. This mono-activity has been responsible for the current tourism crisis in all its dimensions: economic, social and environmental. The political instability that followed the 2011 revolution, as well as the attacks that hit Tunisia in 2015, have drastically reduced tourist numbers in the country. These political and security crises have been caught up in its recovery by the COVID-19. In fact, the pandemic context would have served as an indicator and gas pedal of the development of a "sustainable tourism" in place of the mass tourism of the preCOVID. [ABSTRACT FROM AUTHOR]

This work investigated the removal of phenol from petroleum wastewater by the electro‐oxidation process. The experimental design was developed on a pilot‐scale electro‐oxidation system equipped with a cylindrical shape of graphite electrodes as an anode and stainless‐steel electrodes as a cathode. An initial study was performed based on operating variables such as current density and time on real petroleum wastewater. The optimum conditions were obtained as a current density of 3 mA/cm2 and time 15 min. Under these applied optimum conditions, complete phenol removal from an initial concentration of about 6.8 mg/L was achieved. Also, 50–60% removal of organic matter in terms of chemical oxygen demand (COD) and biological oxygen demand (BOD). The removal of organic matter using electro‐oxidation requires a long reaction time. Also, the economic study indicated that the energy consumption was determined to be 0.79 kWh/m3 and the operating cost was 0.051 $/m3 which is very economical compared with conventional methods. [ABSTRACT FROM AUTHOR]

The performance of a multistage passively aerated biological filter (PABF) packed with Nonwoven polyester fabric (NWPF) for municipal wastewater treatment was investigated under different operating conditions. The system was operated at different hydraulic retention times (HRTs) of 2.3, 1.72 and 1.38 h and corresponding to organic loading rates (OLRs) of 1.77, 2.15 and 2.9 kg BOD/m3. d. Increasing HRT and decreasing OLR, increased dissolved oxygen (DO) and consequently increased the removal rate of organic matters (87%), suspended solids (95.8%) and ammonia (88%). Profile results from different compartments showed that the major part of organic and suspended matters was removed in the upper layers of the system, whereas most of the suspended solids were trapped, while the nitrification process took place in the lower part of the PABF system because of the increase in DO concentrations. The results proved the advantage of using NWPF. It has pleated and rough surface which retain more biomass compared with plain surface. Excess biomass produced from PABF was negligible compared to conventional treatment systems. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the efficiency of a novel pilot-scale passively aerated biological filter (PABF) as a low energy consumption system for the treatment of municipal wastewater. It consists of four similar compartments, each containing 40% of a non-woven polyester fabric as a bio-bed. The PABF was fed with primary treated wastewater under a hydraulic retention time (HRT) of 3.5 hr and a hydraulic loading rate of 5.5 m2/m3/d. The effect of media depth, HRT, dissolved oxygen (DO) and surface area of the media on the removal efficiency of pollutants was investigated. Results indicated that increasing media depth along the axis of the reactor and consequently increasing the HRT and DO resulted in great removal of different pollutants. A significant increase in the DO levels in the final effluent up to 6.7 mg/l resulted in good nitrification processes. Statistical analysis using SPSS showed that the reactor performance has significant removal efficiency (p < .05) for all pollutants. Overall results indicated that PABF is a viable ecological engineering approach that can be optimized and applied to improve water quality with minimal consumption of energy and low sludge production compared with conventional activated sludge and trickling filter systems. [ABSTRACT FROM AUTHOR]